Rockslide was brought to the Age of Apocalypse along with his fellow students after they engaged X-Man in a conversation. Not knowing how they got there the group decided to split up due to differences in opinion. For the past couple of months, Rockslide traveled with Pixie as they made their way through the treacherous terrain formerly known as Chicago.
They came across a mutant scavenger who had information to sell involving the location of their former comrades. Rockslide grabbed him by the head while mentioning that if he told them about the news then they would repay him by sparing his life. The duo came upon an empty building which made Rockslide mad thinking that the creep sold them on a lie but Pixie realized there was condensation on the window which meant the building had occupants within. She told Rockslide to stay put while she went on a recruitment drive to get these other mutants to help them against X-Man.
But Rockslide became impatient and headed to Sinister's lab on his own to confront Glob and Armor. Taking them by surprise, he was eventually joined by Pixie and the group who she got to join them. A fight broke out between the two sides with Pixie teleporting Nate into one of the pods as it started to fill up with some kind of liquid. Rockslide and Glob duked it out with the both of them equal in size and strength. But the battle was halted as Armor took it upon herself to kill Nate after listening to Pixie's rhetoric.
But X-Man was saved by Bishop who fired a concussive blast directly at Armor knocking her on the ground. Santo was so happy to finally see the arrival of the X-Men, but after Hisako powered down she conveyed that no one else was coming there besides Bishop. She blamed the X-Men for abandoning them after all these years but Bishop told her that they have only been gone for five minutes.
He said that they had been pulled into Legion's subconscious that acted like an alternate reality. All of a sudden Legion appeared and began a telepathic battle against Nate on the astral plane. Rockslide watched as the both of them just stood there staring at each. But all of a sudden a bright flash of light engulfed Santo and the others bringing them out of Legion's mind and back into the real world.